Investigators from across Europe said on Monday they had identified about 380 football matches that had been fixed across Europe, bringing in about 8 million euros in profits.

Speaking in The Hague, Europol head Rob Wainright said the joint investigation had identified about 425 corrupt officials, players and serious criminals in 15 countries.

"This is a sad day for European football," Wainwright said.

He said a Singapore-based criminal network was involved in the match fixing, spending up to 100,000 euros (£86,000) per match to bribe players and officials.

Wainwright refused to identify any of the suspects, players or matches involved, citing ongoing investigations.

He said while many fixed matches were already known, the Europol investigation lifted the lid on the widespread involvement or organised crime in rigging games.

"This is the first time we have established substantial evidence that organised crime is now operating in the world of football," he said.

Matches fixed included World Cup and European Championship qualifying matches and top flight league matches in several European countries. The investigator found that criminals from Asia also participated in the match fixing and that some of the fixed matches took place outside Europe.

One of the matches identified is an unnamed Champions League game taking place in England, though the identity of the match cannot be confirmed due to "ongoing judicial proceedings".

Wainwright has revealed it occurred in the last three to four years, adding: "The focus has been on other countries, not the United Kingdom. However we were surprised by the scale generally of the criminal enterprise and just how widespread it was.

"It would be naive and complacent of those in the UK to think such a criminal conspiracy does not involved the English game and all the football in Europe."

He continued: " This is the work of a suspected organised crime syndicate based in Asia and operated with criminal networks around Europe.

"It is clear to us this is the biggest-ever investigation into suspected match-fixing in Europe. It has yielded major results which we think have uncovered a big problem for the integrity of football in Europe.

"We have uncovered an extensive criminal network."

UEFA said it expected to receive further information from Europol in the coming days.

"As part of the fight against the manipulation of matches, UEFA is already cooperating with the authorities on these serious matters as part of its zero tolerance policy towards match-fixing in our sport," it added.

A German investigator described a network involving couriers ferrying bribes around the world, paying off players and referees in the fixing which involved about 425 corrupt officials, players and serious criminals in 15 countries.

"We have evidence for 150 of these cases, and the operations were run out of Singapore with bribes of up to 100,000 euros paid per match," said Friedhelm Althans, chief investigator for police in the German city of Bochum, told a news conference.

Althans said that, though German police had concrete proof of 8 million euros in gambling profits from the match fixing, this was probably the tip of the iceberg.

Investigators described how gang members immediately subordinate to the Singapore-based leader of a worldwide network were each tasked with maintaining contacts with corrupt players and officials in their parts of the world.

Laszlo Angeli, a Hungarian prosecutor, gave an example of how the scam worked. "The Hungarian member, who was immediately below the Singapore head, was in touch with Hungarian referees who could then attempt to swing matches at which they officiated around the world," he said.

Accomplices would then place bets on the internet or by phone with bookmakers in Asia, where bets that would be illegal in Europe were accepted. "One fixed match might involve up to 50 suspects in 10 countries on separate continents," said Althans.

"Even two World Cup qualification matches in Africa, and one in Central America, are under suspicion," Althans added.

FIFA issued a statement pointing to quotes from its Director of Security, Ralf Mutschke, before a match-fixing conference in Rome last month.

"World Cup qualifying matches are tough to fix as a general rule, since the World Cup is the biggest event for teams and above all players," he said. "We're obviously still keeping a very close eye on the matches, but as yet there have been no suspicions of fixing."

Althans said there was a need to coordinate match fixing legislation around Europe. "In many countries, including Germany, fixing a match only becomes a crime if you then place a bet on the outcome," he said, adding that proving a bet had been placed was often difficult.